US3548862A - Control system for a gas discharger - Google Patents

Description

United States Patent [72] lnventors ltsuro Nakamura;

Yasuo Takeichi; Teruo Saito, Tokyo, Japan [21] Appl. No. 757,953

[22] Filed Sept. 6, 1968 [45] Patented Dec. 22, 1970 [73] Assignee Yutakn Sangyo Kabushikikaisha Tokyo, Japan [32] Priority Apr. 27, 1968 [33] Japan [31] No. 43/28112 [54] CONTROL SYSTEM FOR A GAS DISCHARGER 3 Claims, 2 Drawing Figs.

[52] U.S. 137/340, 137/505.12 [51] Int. Cl. ..Fl6k 49/00, F161: 31/12 [50] Field ofSeareh 137/340, 505.12, 557

[56] References Cited UNITED STATES PATENTS 1,660,842 2/1928 Hoesel 137/505.12

a 2 3 1 9 2 I/O 17 I2 25,- 26 34/37 5 I I V l Y IIIT/ Primary Examiner-Henry T. Klinksiek Attorney-Davis, Hoxie, Faithfull and Hapgood ABSTRACT: A control system for discharging gas from a reservoir of liquefied carbon dioxide where a main body comprising the first, second and third valves for depressing gas pressure fixed therein, said first valve communicates with the second valve through a perforated passage 8; said second valve communicates with an expanded space formed therearound through a passage 17; said expanded space communicates with the third valve through a passage 24; a chamber for depressing gas pressure of said third valve communicates with a screwed passage 26 formed in said main body through a perforated passage 29, and a rear end of said screwed passage communicates with a gauge fixed to said main body.

PATENTED nc22|9m 3.548362 FIG. 1

FIG. 2

Itsuro Nakamura Yasuo Takeichi Teruo Saito INVENTORs BY Davis, Hoxie, Faithfull &

Hapgood I Attorneys CONTROL SYSTEM FOR A GAS DISCHARGER BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control system for a carbon dioxide discharger controlling the pressure of CO gas in the system supplied from a reservoir of the liquified gas.

2. Description of the Prior Art A gas discharger of this kind, generally used hitherto, and a passage of small diameter for the gas and had a small space for reducing gas pressure. This discharger easily became blocked by solidification of thegas to dry ice due to cooling along the passage during gasifying from the liquid. As a result the passage became impeded and the gas'pressure or amount of gas flow decreased. Moreover, the flow of gas became uncontrollable, when there was a continuous release of large amounts of gas.

For the purpose of preventing those faults, an electric heater or a warming device using warm water was employed in the structure, with the result that the construction became complicated and difficult to manufacture. Also, damage due to the heater or the warming device occurred frequently, despite the greater expense and complexity.

SUMMARY OF THE INVENTION The object of the present invention isto provide an improved gas discharger which overcomes the defects mentioned above. x

According to the present invention, the flow of gas in a con trol system of a gas discharger is controlled by a first valve a which communicates with a second valve b through a first passage 8 which restricts and exercises a compressive action on the flowing gas. The second valve communicates with an expansion chamber 18 formed therearound through a second passage 17 which again restricts and exercises a compressive action on the flowing gas. The expansion chamber 18 communicates with the third valve r: c through a third passage 24 to again restrict and exercise a compressive action on the gas flow. A chamber. 28 for reducing gas pressure surrounds the third valve and communicates with a helical passage 26 formed in an inner casing 19 through a'restrictive passage 29. In said helical passage 26 the cold gas absorbs heat by contacting with the inside of the main body. which has fins 1 therearound, before it enters into the casing of a gauge 35.

During the process the gas is subjected to several successive compressive actions as it passes through the valves and repeatedly expands. Thus the gas flows in an irregular fashion so that the rate of heat-exchange is effective and a cooling action of the gasified liquid upon the passages through which it flows, is reduced. Accordingly the phenomenon of solidifying gas into dry ice" does not occur, despite the absence of any heating device; and freezing within the passages does not occur.

The diameters of the passages for the gas, especially those of the valve-openings can be enlarged for more effective flow of the gas; and the flow can be controlled accurately during continuous discharge of a large amount of carbon dioxide gas.

BRIEF DESCRIPTION OF TI-IEDRAWINGS FIG. 1 is an elevated longitudinal cross-sectional view through a device embodying the invention.

FIG. 2 is an end elevation view of the device of FIG. 1.

DETAILED DESCRIPTION The parts of the invention are mounted in-or on a multipart main body 2 of generally elongated cylindrical shape having heat absorbing fins 1 around its periphery along its length. For convenience in description, reference will be made hereinafter to right" and left as indicating position and locations in F IG. 1. But. it will be understood that such references are used merely for convenience and not in a limiting sense. A first valve, designated as a whole by letter a, has a hollow casing 4 mounted on the body 2 in a radially extending position by a screw-threaded connection. Inside the valve casing 4 is a controllable valve 3 for reducing the pressure of gas entering the valve casing from above (referring to FIG. 1).

The gas passing through the casing 4 exits through a narrow flow restricting passage in an end part of the main body lead ing to a throttle valve, designated as awhole by letter b, for further reducing the gas pressure. Valve-bcomprises a tubular casing 5 exteriorly screw-threaded at one end for mounting in an interiorly screw-threaded recess at the exit end of the passage 8. Within an axial bore or chamber in the casing 5 of the second valve is movable valve member 6 adapted to be seated upon or adjustably spaced from an apertured valve seat 10 midway along the valve casing. The valve member 6 is biased toward the seat 10 by a coiled compression spring 9 in the chamber 7 in one end (the left end in FIG. 1) of the casing 5. The valve member 6 is connected by an axially extending stem or rod 14, inserted through the aperture 11 of the valve seat 10, to an axially extending control bar or element 13 located in another axial chamber 12 (at the right end in FIG. 1) of the tubular casing 5. An adjusting screw 16 is mounted axially by a screw-thread connection in the right end of the tu-' bular casing 5 and engages the control element 13 through a coiled compression spring 15. As the screw 16 is screwed into the casing the valve 6 is lifted from the seat 10 the desired distance.

The left chamber 7 communicates with the-right chamber through the aperture 11 in the valve seat when the valve 6 is off the seat 10.

Coaxially positioned within the right end part of the main body 2 in an inner body 19 which is of cylindrical form, closed at its right end and abutting at its left end against a transverse wall of the left end part of the body 2. The inner body 10 surrounds the valve b and is spaced therefrom providing an annular expansion chamber 18. For communication into chamber 18 from valve chamber 12 one or more radial bores or passages 17 are provided in the wall of the valve chamber 12.

From the chamber 18 communication is provided at the left end into a chamber 23 of a third throttle valve, designated as a whole by letter c, through a short narrow flow-restricting passage 24. The valve 0 is mounted by a screw-thread connec tion in the chamber 23 which is formed as a recess in the left or head portion of the main body 2. A movable valve member 22 is biased by a coiled compression spring 20 toward an apertured valve seat 21.

For adjusting or regulating valve c, an adjustment screw 30 is mounted in a screw-threaded hole. 148 in a cap member secured the left 134 137 128 144 of the body 2. The inner end of the screw 30 is formed to engageone end of a coiled compression spring 31 whose other end engages a seat member on a diaphragm 27 which is secured between the aforementioned cap and head members. The diaphragm covers an expansion chamber 28 formed as a cavity in the left side of the head part of the main body 2 around the valve c. Secured to the inner face of the diaphragm is the head of a member having a projection or stem 32 extending coaxially with the screw 30 and spring 31 and diaphragm 27, through the aperture 33 in the seat 21 of the valve C and engaging the movable valve member 22. As the adjustment screw 30 is manipulated, the spring 31 presses more or less strongly on the diaphragm, whose movement is transmitted by the stem 32 to the movable valve member 22. Thus the movement of the diaphragm alters the space between the valve member 22 and its seat 21 and controls the flow through the valve.

Gas flows from the pressure reduction chamber 28 through a restrictive narrow passage 29 to a helical passage 26 formed in the peripheral surface of the inner body 19 and between that surface and the inner surface of the main body 2. This helical passage runs from the exit end of the narrow connecting passage 29 to the opposite end of the inner body 19 where it connects with a longitudinally extending passage 34 leading to a holder of gas pressure receiver 37 of a pressure indicator 36 included in a gauge 35 fixed to the right end of the main body 2.

The inside of the gauge 35 communicates with a delivering or outlet duct or pipe 40 having a valve 39 connected therein.

With the foregoing in mind the following description of the operation of the invention may be understood.

Carbon dioxide in gasous form from a reservoir containing the liquified gas, passes into the first valve a having its pressure reduced by the throttling action of the valve member 3. The gas flow is impeded and expansion of the gas is retarded as the gas is subjected to a compressive action whilst passing through passage 8 as the gas comes into the chamber 7 of the second valve b. Again, the gas is throttled by passing through the restricted space between the valve member 6 and its seat 10 and then through the aperture 11 in the valve seat from whence the gas passes through restricted orifices 17 into the expansion chamber 18. The expanding gas then is delivered to the third valve 0 through the passage 24 wherein the gas flow is retarded and the gas is subject to compressive action by the size and restrictive nature of such passage. The third valve further reduces the pressu'e of the gas a third time as it is delivered from the valve into expansion chamber 28.

Following the third pressure reduction, the gas is delivered to the restrictive flow passage 29 wherein for the third time the flow is restricted and the expansion halted by the compressive action of the restrictive flow passage 29. From passage 29 the flow is into the helical passage wherein heat is absorbed from the relatively warmer wall of the main body 2, until the gas flows into and then out of the casing of the gauge 35 for final discharge through outlet control valve 39.

Although the present invention has been described in conjunction with a preferred embodiment, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention, as those skilled in the art will readily understand.

We claim:

1. A control system for discharge of gas from a reservoir of carbon dioxide liquid, comprising a main body, first, second and third valve means for reducing gas pressure in successive stages, means providing gas flow, communication from said first valve means to saidsecond valve-means, an expansion chamber surrounding said second valve-means, means providing gas flow communication from said second valve means to said expansion chamber, means providing gas flow communication from said expansion chamber to said third valve means, a pressure reduction chamber connected with said third valve means, and a helical heat exchange passage within said main body and connected with said pressure reduction chamber.

2. A control system as claimed in claim 1 in which the means providing gas flow communication to each successive valve means is a restrictive passage exercising a compressive effect on the gas entering it.

3. A control system as claimed in claim 1 having a restrictive passage between said pressure reduction chamber and said helical heat exchange passage.

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